gdb/regcache.h

   1 /* Cache and manage the values of registers for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2018 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef REGCACHE_H
  21 #define REGCACHE_H
  22
  23 #include "common-regcache.h"
  24 #include <forward_list>
  25
  26 struct regcache;
  27 struct regset;
  28 struct gdbarch;
  29 struct address_space;
  30
  31 extern struct regcache *get_current_regcache (void);
  32 extern struct regcache *get_thread_regcache (ptid_t ptid);
  33 extern struct regcache *get_thread_arch_regcache (ptid_t, struct gdbarch *);
  34 extern struct regcache *get_thread_arch_aspace_regcache (ptid_t,
  35                                                          struct gdbarch *,
  36                                                          struct address_space *);
  37
  38 extern enum register_status
  39   regcache_raw_read_signed (struct regcache *regcache,
  40                             int regnum, LONGEST *val);
  41
  42 extern void regcache_raw_write_signed (struct regcache *regcache,
  43                                        int regnum, LONGEST val);
  44 extern void regcache_raw_write_unsigned (struct regcache *regcache,
  45                                          int regnum, ULONGEST val);
  46
  47 /* Return the register's value in signed or throw if it's not
  48    available.  */
  49
  50 extern LONGEST regcache_raw_get_signed (struct regcache *regcache,
  51                                         int regnum);
  52
  53 /* Read a register as a signed/unsigned quantity.  */
  54 extern enum register_status
  55   regcache_cooked_read_signed (struct regcache *regcache,
  56                                int regnum, LONGEST *val);
  57 extern enum register_status
  58   regcache_cooked_read_unsigned (struct regcache *regcache,
  59                                  int regnum, ULONGEST *val);
  60 extern void regcache_cooked_write_signed (struct regcache *regcache,
  61                                           int regnum, LONGEST val);
  62 extern void regcache_cooked_write_unsigned (struct regcache *regcache,
  63                                             int regnum, ULONGEST val);
  64
  65 /* Special routines to read/write the PC.  */
  66
  67 /* For regcache_read_pc see common/common-regcache.h.  */
  68 extern void regcache_write_pc (struct regcache *regcache, CORE_ADDR pc);
  69
  70 /* Mapping between register numbers and offsets in a buffer, for use
  71    in the '*regset' functions below.  In an array of
  72    'regcache_map_entry' each element is interpreted like follows:
  73
  74    - If 'regno' is a register number: Map register 'regno' to the
  75      current offset (starting with 0) and increase the current offset
  76      by 'size' (or the register's size, if 'size' is zero).  Repeat
  77      this with consecutive register numbers up to 'regno+count-1'.
  78
  79    - If 'regno' is REGCACHE_MAP_SKIP: Add 'count*size' to the current
  80      offset.
  81
  82    - If count=0: End of the map.  */
  83
  84 struct regcache_map_entry
  85 {
  86   int count;
  87   int regno;
  88   int size;
  89 };
  90
  91 /* Special value for the 'regno' field in the struct above.  */
  92
  93 enum
  94   {
  95     REGCACHE_MAP_SKIP = -1,
  96   };
  97
  98 /* Transfer a set of registers (as described by REGSET) between
  99    REGCACHE and BUF.  If REGNUM == -1, transfer all registers
 100    belonging to the regset, otherwise just the register numbered
 101    REGNUM.  The REGSET's 'regmap' field must point to an array of
 102    'struct regcache_map_entry'.
 103
 104    These functions are suitable for the 'regset_supply' and
 105    'regset_collect' fields in a regset structure.  */
 106
 107 extern void regcache_supply_regset (const struct regset *regset,
 108                                     struct regcache *regcache,
 109                                     int regnum, const void *buf,
 110                                     size_t size);
 111 extern void regcache_collect_regset (const struct regset *regset,
 112                                      const struct regcache *regcache,
 113                                      int regnum, void *buf, size_t size);
 114
 115
 116 /* The type of a register.  This function is slightly more efficient
 117    then its gdbarch vector counterpart since it returns a precomputed
 118    value stored in a table.  */
 119
 120 extern struct type *register_type (struct gdbarch *gdbarch, int regnum);
 121
 122
 123 /* Return the size of register REGNUM.  All registers should have only
 124    one size.  */
 125
 126 extern int register_size (struct gdbarch *gdbarch, int regnum);
 127
 128 typedef gdb::function_view<register_status (int regnum, gdb_byte *buf)>
 129   register_read_ftype;
 130
 131 /* A (register_number, register_value) pair.  */
 132
 133 typedef struct cached_reg
 134 {
 135   int num;
 136   gdb_byte *data;
 137 } cached_reg_t;
 138
 139 /* Buffer of registers.  */
 140
 141 class reg_buffer : public reg_buffer_common
 142 {
 143 public:
 144   reg_buffer (gdbarch *gdbarch, bool has_pseudo);
 145
 146   DISABLE_COPY_AND_ASSIGN (reg_buffer);
 147
 148   /* Return regcache's architecture.  */
 149   gdbarch *arch () const;
 150
 151   /* See common/common-regcache.h.  */
 152   enum register_status get_register_status (int regnum) const override;
 153
 154   /* See common/common-regcache.h.  */
 155   void raw_collect (int regnum, void *buf) const override;
 156
 157   /* Collect register REGNUM from REGCACHE.  Store collected value as an integer
 158      at address ADDR, in target endian, with length ADDR_LEN and sign IS_SIGNED.
 159      If ADDR_LEN is greater than the register size, then the integer will be
 160      sign or zero extended.  If ADDR_LEN is smaller than the register size, then
 161      the most significant bytes of the integer will be truncated.  */
 162   void raw_collect_integer (int regnum, gdb_byte *addr, int addr_len,
 163                             bool is_signed) const;
 164
 165   /* See common/common-regcache.h.  */
 166   void raw_supply (int regnum, const void *buf) override;
 167
 168   void raw_supply (int regnum, const reg_buffer &src)
 169   {
 170     raw_supply (regnum, src.register_buffer (regnum));
 171   }
 172
 173   /* Supply register REGNUM to REGCACHE.  Value to supply is an integer stored
 174      at address ADDR, in target endian, with length ADDR_LEN and sign IS_SIGNED.
 175      If the register size is greater than ADDR_LEN, then the integer will be
 176      sign or zero extended.  If the register size is smaller than the integer,
 177      then the most significant bytes of the integer will be truncated.  */
 178   void raw_supply_integer (int regnum, const gdb_byte *addr, int addr_len,
 179                            bool is_signed);
 180
 181   /* Supply register REGNUM with zeroed value to REGCACHE.  This is not the same
 182      as calling raw_supply with NULL (which will set the state to
 183      unavailable).  */
 184   void raw_supply_zeroed (int regnum);
 185
 186   void invalidate (int regnum);
 187
 188   virtual ~reg_buffer () = default;
 189
 190   /* See common/common-regcache.h.  */
 191   bool raw_compare (int regnum, const void *buf, int offset) const override;
 192
 193 protected:
 194   /* Assert on the range of REGNUM.  */
 195   void assert_regnum (int regnum) const;
 196
 197   int num_raw_registers () const;
 198
 199   gdb_byte *register_buffer (int regnum) const;
 200
 201   /* Save a register cache.  The set of registers saved into the
 202      regcache determined by the save_reggroup.  COOKED_READ returns
 203      zero iff the register's value can't be returned.  */
 204   void save (register_read_ftype cooked_read);
 205
 206   struct regcache_descr *m_descr;
 207
 208   bool m_has_pseudo;
 209   /* The register buffers.  */
 210   std::unique_ptr<gdb_byte[]> m_registers;
 211   /* Register cache status.  */
 212   std::unique_ptr<register_status[]> m_register_status;
 213
 214   friend class regcache;
 215   friend class detached_regcache;
 216 };
 217
 218 /* An abstract class which only has methods doing read.  */
 219
 220 class readable_regcache : public reg_buffer
 221 {
 222 public:
 223   readable_regcache (gdbarch *gdbarch, bool has_pseudo)
 224     : reg_buffer (gdbarch, has_pseudo)
 225   {}
 226
 227   /* Transfer a raw register [0..NUM_REGS) from core-gdb to this regcache,
 228      return its value in *BUF and return its availability status.  */
 229
 230   enum register_status raw_read (int regnum, gdb_byte *buf);
 231   template<typename T, typename = RequireLongest<T>>
 232   enum register_status raw_read (int regnum, T *val);
 233
 234   /* Partial transfer of raw registers.  Return the status of the register.  */
 235   enum register_status raw_read_part (int regnum, int offset, int len,
 236                                       gdb_byte *buf);
 237
 238   /* Make certain that the register REGNUM is up-to-date.  */
 239   virtual void raw_update (int regnum) = 0;
 240
 241   /* Transfer a raw register [0..NUM_REGS+NUM_PSEUDO_REGS) from core-gdb to
 242      this regcache, return its value in *BUF and return its availability status.  */
 243   enum register_status cooked_read (int regnum, gdb_byte *buf);
 244   template<typename T, typename = RequireLongest<T>>
 245   enum register_status cooked_read (int regnum, T *val);
 246
 247   /* Partial transfer of a cooked register.  */
 248   enum register_status cooked_read_part (int regnum, int offset, int len,
 249                                          gdb_byte *buf);
 250
 251   /* Read register REGNUM from the regcache and return a new value.  This
 252      will call mark_value_bytes_unavailable as appropriate.  */
 253   struct value *cooked_read_value (int regnum);
 254
 255 protected:
 256
 257   /* Perform a partial register transfer using a read, modify, write
 258      operation.  Will fail if register is currently invalid.  */
 259   enum register_status read_part (int regnum, int offset, int len,
 260                                   gdb_byte *out, bool is_raw);
 261 };
 262
 263 /* Buffer of registers, can be read and written.  */
 264
 265 class detached_regcache : public readable_regcache
 266 {
 267 public:
 268   detached_regcache (gdbarch *gdbarch, bool has_pseudo)
 269     : readable_regcache (gdbarch, has_pseudo)
 270   {}
 271
 272   void raw_update (int regnum) override
 273   {}
 274
 275   DISABLE_COPY_AND_ASSIGN (detached_regcache);
 276 };
 277
 278 class readonly_detached_regcache;
 279
 280 /* The register cache for storing raw register values.  */
 281
 282 class regcache : public detached_regcache
 283 {
 284 public:
 285   DISABLE_COPY_AND_ASSIGN (regcache);
 286
 287   /* Return REGCACHE's address space.  */
 288   const address_space *aspace () const
 289   {
 290     return m_aspace;
 291   }
 292
 293   /* Restore 'this' regcache.  The set of registers restored into
 294      the regcache determined by the restore_reggroup.
 295      Writes to regcache will go through to the target.  SRC is a
 296      read-only register cache.  */
 297   void restore (readonly_detached_regcache *src);
 298
 299   /* Update the value of raw register REGNUM (in the range [0..NUM_REGS)) and
 300      transfer its value to core-gdb.  */
 301
 302   void raw_write (int regnum, const gdb_byte *buf);
 303
 304   template<typename T, typename = RequireLongest<T>>
 305   void raw_write (int regnum, T val);
 306
 307   /* Transfer of pseudo-registers.  */
 308   void cooked_write (int regnum, const gdb_byte *buf);
 309
 310   template<typename T, typename = RequireLongest<T>>
 311   void cooked_write (int regnum, T val);
 312
 313   void raw_update (int regnum) override;
 314
 315   /* Partial transfer of raw registers.  Perform read, modify, write style
 316      operations.  */
 317   void raw_write_part (int regnum, int offset, int len, const gdb_byte *buf);
 318
 319   /* Partial transfer of a cooked register.  Perform read, modify, write style
 320      operations.  */
 321   void cooked_write_part (int regnum, int offset, int len,
 322                           const gdb_byte *buf);
 323
 324   void supply_regset (const struct regset *regset,
 325                       int regnum, const void *buf, size_t size);
 326
 327
 328   void collect_regset (const struct regset *regset, int regnum,
 329                        void *buf, size_t size) const;
 330
 331   /* Return REGCACHE's ptid.  */
 332
 333   ptid_t ptid () const
 334   {
 335     gdb_assert (m_ptid != minus_one_ptid);
 336
 337     return m_ptid;
 338   }
 339
 340   void set_ptid (const ptid_t ptid)
 341   {
 342     this->m_ptid = ptid;
 343   }
 344
 345 /* Dump the contents of a register from the register cache to the target
 346    debug.  */
 347   void debug_print_register (const char *func, int regno);
 348
 349   static void regcache_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid);
 350 protected:
 351   regcache (gdbarch *gdbarch, const address_space *aspace_);
 352   static std::forward_list<regcache *> current_regcache;
 353
 354 private:
 355
 356   void transfer_regset (const struct regset *regset,
 357                         struct regcache *out_regcache,
 358                         int regnum, const void *in_buf,
 359                         void *out_buf, size_t size) const;
 360
 361   /* Perform a partial register transfer using a read, modify, write
 362      operation.  */
 363   enum register_status write_part (int regnum, int offset, int len,
 364                                    const gdb_byte *in, bool is_raw);
 365
 366   /* The address space of this register cache (for registers where it
 367      makes sense, like PC or SP).  */
 368   const address_space * const m_aspace;
 369
 370   /* If this is a read-write cache, which thread's registers is
 371      it connected to?  */
 372   ptid_t m_ptid;
 373
 374   friend struct regcache *
 375   get_thread_arch_aspace_regcache (ptid_t ptid, struct gdbarch *gdbarch,
 376                                    struct address_space *aspace);
 377
 378   friend void
 379   registers_changed_ptid (ptid_t ptid);
 380 };
 381
 382 class readonly_detached_regcache : public readable_regcache
 383 {
 384 public:
 385   readonly_detached_regcache (regcache &src);
 386
 387   /* Create a readonly regcache by getting contents from COOKED_READ.  */
 388
 389   readonly_detached_regcache (gdbarch *gdbarch, register_read_ftype cooked_read)
 390     : readable_regcache (gdbarch, true)
 391   {
 392     save (cooked_read);
 393   }
 394
 395   DISABLE_COPY_AND_ASSIGN (readonly_detached_regcache);
 396
 397   void raw_update (int regnum) override
 398   {}
 399 };
 400
 401 extern void registers_changed (void);
 402 extern void registers_changed_ptid (ptid_t);
 403
 404 /* An abstract base class for register dump.  */
 405
 406 class register_dump
 407 {
 408 public:
 409   void dump (ui_file *file);
 410   virtual ~register_dump () = default;
 411
 412 protected:
 413   register_dump (gdbarch *arch)
 414     : m_gdbarch (arch)
 415   {}
 416
 417   /* Dump the register REGNUM contents.  If REGNUM is -1, print the
 418      header.  */
 419   virtual void dump_reg (ui_file *file, int regnum) = 0;
 420
 421   gdbarch *m_gdbarch;
 422 };
 423
 424 #endif /* REGCACHE_H */